Dumbwaiter loading and unloading apparatus

ABSTRACT

A dumbwaiter loading and unloading apparatus employing a motor driven belt unit is mounted on the dumbwaiter platform and arranged to project a carriage outwardly of the platform at a selected landing level. The carriage is provided with a moving belt reversibly driven to cooperate with a worktable stationed at a selected landing level. The worktable is provided with a slave belt that is driven by the belt drive in the dumbwaiter apparatus in a direction to move a load out of the unit onto the worktable or to move the load from the table onto the dumbwaiter apparatus.

United States Patent [191 Brockmeyer et al.

DUMBWAITER LOADING AND UNLOADING APPARATUS Security Fire Door Company,St. Louis, Mo.

Filed: Sept. 13, 1971 Appl. No.: 180,204

Related U.S. Application Data Continuation of Ser. No. 856,389, Sept. 9,1969, abandoned.

Assignee:

U.S. Cl ..214/16.4 R, 214/161 CF, 214/730 Int. Cl. B65g l/06 Field ofSearch 2l4/l6.l CF, 16.4 R,

References Cited UNITED STATES PATENTS l/l963 Sylvester et al 214/164 AJan. 1, 1974 3,036,722 5/1962 Sharaway 214/46 3,237,789 3/1966 Guilbert,Jr 214/164 R Primary Examiner-Gerald M. Forlenza AssistantExaminer-Lawrence J. Oresky Alt0rneyGravely, Leider & Woodruff [57]ABSTRACT A dumbwaiter loading and unloading apparatus employing a motordriven belt unit is mounted on the dumbwaiter platform and arranged toproject a carriage outwardly of the platform at a selected landinglevel. The carriage is provided with a moving belt reversibly driven tocooperate with a worktable stationed at a selected landing level. Theworktable is provided with a slave belt that is driven by the belt drivein the dumbwaiter apparatus in a direction to move a load out of theunit onto the worktable or to move the load from the table onto thedumbwaiter apparatus.

6 Claims, 14 Drawing Figures PAN. 75mm 197 sum 2 or Q, Q Q Q R QPATENTED W SHEET t [If 6 DUMBWAITER LOADING AND UNLOADING APPARATUS Thisis a continuation of application Ser. No. 856,389 filed Sept. 9, 1969,now abandoned.

BACKGROUND-OF THE INVENTION This invention relates to loading andunloading of dumbwaiters, elevators, lifts, and conveyor apparatus, andis particularly concerned with the art of material handling systems.

Material handling systems have been adapted to a wide variety ofapplications in industrial and commercial settings. In order toaccommodate the systems to the various applications, expensive andcomplicated apparatus and controls have been devised. A majority of theapplications have been in handling materials and articles in generalhorizontal travel. Simplicity of construction and reliability ofoperation has not been carried out so that the systems are expensive andnot within the reach or needs of certain business and manufacturingoperations. This is especially the case with service institutions, suchas hospitals and like institutrons.

BRIEF DESCRIPTION OF THE INVENTION The present invention is directed tosimple and inexpensive apparatus for loading and unloading articles andthe like in a reliable manner and under the control of manual orautomatic devices located at a plurality of stations. The apparatusincludes a power operated unit that moves along a predetermined path andcouples itself to a preselected article supporting means at the severalstations spaced along the path.

A preferred form of apparatus is adapted for use with a dumbwaitersystem movable to floor levels of a multifloor institution. Thedumbwaiter is provided with a unit on which a belted carriage is movableoutwardly of the dumbwaiter shaft to engage the article supportingtable. The table is provided with a slave belt that is activated by thecarriage belt drive to receive articles or to deliver articles onto thecarriage belt. The apparatus is provided with components and parts thatwill be more particularly set forth and described in the specificationto follow.

BRIEF DESCRIPTION OFTHE DRAWINGS In the drawings forming a part of thespecification of the apparatus:

FIG. 1 is a fragmentary plan view of a typical organization ofcomponents suitable for a dumbwaiter system;

FIG. 2 is a fragmentary sectional view seen at line 2-2 in FIG. 1;

FIG. 3 is an enlarged and partly broken away plan view of the loadingand unloading unit mounted on the dumbwaiter seen in FIG. 1;

FIG. 4 is a sectional elevational view of the dumbwaiter loading andunloading apparatus, the view being taken along line 4--4 in FIG. 3;

FIG. 5 is a fragmentary transverse sectional view taken along line 5--5in FIG. 4;

FIG. 6 is a further fragmentary sectional view as seen at line 6-6 inFIG. 5;

FIG. 7 is a further longitudinal sectional elevational view, similar toFIG. 4, but taken along line 7-7 in FIG. 3;

FIG. 8 is a greatly enlarged fragmentary plan view of the drive chainslack compensator, the view being taken at line 8-8 in FIG. 7;

FIG. 9 is a transverse sectional elevational view taken at line 9--9 inFIG. 4;

FIG. 10 is a greatly enlarged fragmentary elevational view taken at line101t) in FIG. 2;

FIG. 1 1 is a fragmentary and fore-shortened sectional elevational viewtaken at line 11-11 in FIG. 10;

FIG. 12 is a fragmentary sectional detailed view as seen at line 12--12in FIG. 11;

FIG. 13 is a fragmentary diagram of the electrical components for thepresent apparatus schematically arranged on the carriage and tables; and

FIG. 14 is a block wiring diagram of the preferred circuit arrangementfor the apparatus of this invention.

DESCRIPTION OF THE DUMBWAITER SYSTEM The present apparatus is designedto be used in a multi-level commercial or institutional building and isembodied in a system as is best seen in FIGS. 1 and 2. As there shown,the building is provided with a lower level floor 20 from which risesvertically a dumbwaiter shaft defined by opposite walls 21 and 22 whichare in turn provided with access or door openings 23 and 24. The dooropening 23 in wall 21 opens outwardly to a service area in which thereispositzioned a table 25 supported on a suitable column or leg structure26. The

door opening 24 in the opposite wall 22 of the vertical shaft issimilarly provided with a table 25, and the tables 25 are located withtheir upper surfaces in approximately the same plane. The view of FIG. 1is a plan view of what is shown in FIG. 2 and is intended to show thatthe door openings 23 and 24 in the respective walls 21 and 22 of theelevator shaft open to service areas on either side of the shaft columnand that the floor 20 can be representative of any floor of amulti-floor structure.

The walls 21 and 22 enclose a dumbwairter elevator car 26 which has alower platform 27 and bi-parting closure gates 28 and 29. The gates 28and 29 at the left hand side adjacent to the door opening 23 are shownin the open position and the gates 28 and 29 at the righthand sideadjacent to the door opening 24 are shown in the closed position. Inaddition, the dumbwaiter shaft itself is provided with bi-parting doors30 and 31, and again the doors 2t) and 31 at the lefthand side are shownin the open position so that the door opening 23 is fully open foraccess to the dumbwaiter car 26. The opposite doors 30 and 31 are shownin a position to close the door opening 24. The shaft doors 30 and 31are set inside the dumbwaiter shaft so that the work-supporting tables25 have ends which are partially set within the door openings 23 and 24for a purpose which will appear presently.

The floor 27 of the dumbwaiter carriage 26 supports the loading andunloading apparatus 32 which, with the work supporting tables 25,constitutes the principle structure of this invention. Briefly, theapparatus includes a stationary frame 33 mounted on the floor 27 and amovable carriage 34 which is operable to move out of the frame 33to theright or the left as is desired so that the carriage can line up withthe adjacent ends of the work supporting tables 25. The apparatus isparticularly intended to handle tote boxes which are shown at B in FIG.2. These boxes may be formed of suitable plastic or other material so asto be durable and yet of sufficient lightweight construction to handleobjects that may be placed in boxes for easy transportation throughout asystem in commercial, industrial, institutional or other buildings inwhich the present invention may be installed.

As may be seen in FIGS. 1 and 2, the car 26 supports a carriage 34 whichis provided with a motor driven belt 35 trained over suitable pulleys 36and 37 at the respective ends. The motor which drives the belt 35 isalso arranged to drive friction rollers 38 and 39 mounted in thecarriage 34. The friction rollers 38 protrude forwardly of the leadingedge of the carriage 34 when it is moved leftwardly as shown in FIGS. 1and 2 and these friction rollers engage with slave friction rollers 40mounted on the adjacent work supporting table 25. The slave rollers 40drive a slave belt 41, and because of the physical position of therespective rollers 38 and 40 the belt 41 will move in the same directionas the belt 35, so that a tote box B moved leftwardly from the carriage34 will be transferred onto the work supporting table 25 by the belt 41so as to clear the dumbwaiter shaft door opening 23. In a similar mannerthe righthand friction rollers 39 on the carriage 34 are intended toengage friction rollers 42 at the adjacent end of the worktable 25 inthe door opening 24 when the carriage 34 is moved rightwardly. This hasthe intended action of driving a slave belt 43 on the worktable 25 sothat a tote box B will be transferred in the same direction as the belt35 is driven. Thus, the carriage 34 can move out toward either of thework supporting tables 24, and the carriage belt 35 may be driven insuch a direction thata tote box B on either of the belts 41 or 43 willbe moved onto the carriage belt 35. The reverse action is, of course,obvious.

In the system shown in fragmentary plan and elevational views in FIGS. 1and 2 it is, of course, understood that the worktables 25 may bestationed at each of the dumbwaiter, access door openings 23 and 24 atthe several floors in a building.

DESCRIPTION OF THE LOADING AND UNLOADING APPARATUS Reference will now bemade principally to FIGS. 3, 4, 5, 7 and 9 for a description of theapparatus 32 mounted on the dumbwaiter floor 27. It is understood thatonly the essential structure and operating components will beparticularly pointed out and described.

The frame for the apparatus may best be seen in FIGS. 4, 7 and 9 andthese views include a floor plate 45 which extends the full length ofthe assembly, pairs of opposite vertical sidewalls 46 which also extenda short distance lengthwise of the assembly, and a pair of longitudinaltop channels 47 supported by the side walls 46 and carry trackways 48 inwhich a plurality of suitable rollers 49 are operable. The rollers 49operably support the frame 50 of the carriage 34. The frame 50 is madein right and left hand parts and those parts provide spaced innerdepending flanges 51 which run longitudinally of the assembly forsupporting certain of the shaft bearings and other parts for operatingcomponents which will be described. The two frames 50 are (FIGS. 4, and9) interconnected by a top plate 52 formed along its longitudinal outeredges by guard channels 53 so as to define a longitudinal passagewayacross the top of the carriage 34 for the purpose of keeping the toteboxes B moving in the correct path of travel. The top plate 52 supportsthe working pass of the belt 35 while the return pass 35a of the beltmoves under the top plate 52. Below plate 52 is a horizontal wall 54attached by flanges 55 to the lower margins of the depending flanges 51.

As may be seen in FIG. 3, the working pass of the belt 35 is trainedover a roller 37 at the right end and at the opposite end over a roller36. The roller 37 has a shaft 56 mounted at its opposite ends insuitable bearings 57 in the respective depending flanges 5li so that itstop surface will support the belt 35 on the top plate 52. The lefthandrollers 36 has a shaft 58 which is mounted (FIGS. 4, 6 and 7) byadjustable bearing means 59 carried by the depending flanges 51 tocomplete the operative support of the belt 35.

As is seen in FIG. 4 the righthand belt driving roller 37 has a gear 60mounted on the cross shaft 56, which gear meshes with a drive gear 61 ona second cross shaft 62 mounted by suitable bearings in the dependingflanges 51 (FIG. 9). The shaft 62 extends beyond flanges 51 and supportsthe friction rollers 39 before referred to in FIGS. 1 and 2. The belt 35forms the drive connection from roller 37 to roller 36 and power inputto shaft 62 is transmitted to the shaft 56 for roller 37 through meshinggears 60 and 61. As seen in FIG. 7, shaft 62 is provided with a sprocketwheel 63 on which a sprocket chain 64 is engaged, and the opposite endof the chain engages on a second sprocket wheel 65 mounted to driveshaft 66 (FIGS. 5 and 7). The shaft 66 extends across the frame andcarries friction wheels 38 at its outboard ends.

The power input to the sprocket chain 64 is best seen in FIGS. 3, 7, 8and 9. A motor 67 has its pulley 68 connected by belt 69 to a pulley 70on shaft 71. The shaft 71 is mounted in spaced frame walls 72 and 73 ofan upwardly opening U-shaped sub-frame 74 in which motor 67 is mounted.The sub-frame 74 also supports a pair of idler shafts 75 spacedsymmetrically (FIG. 7) relative to shaft 71. The shaft 71 carries apower input sprocket 76 about which the chain 64 passes and the shafts75 carry idler sprockets 77 which retain the chain in a desiredcondition of wrap on the input sprocket 76. The chain 64 engages therespective sprockets 63 and 65 on shafts 62 and 66, and the top pass ofthe chain 64 runs through a slack take-up device 78, best seen in FIGS.3, 4, 7 and 8.

The slack take-up device 73 includes a pair of spaced frame members 79and 80 which support shafts 81 and 82 so its sprocket 86 engages thereturn pass of chain 64. Sprocket 84 rides on top of the chain 64 andsprocket 86 rides under the chain. The frame members 79 and 80 aresupported on the end of a shaft 87 which extends across the width of theapparatus and through the depending flanges 51 where on the opposite endthere is affixed a lever 88. The lever 88 is engaged at its lower end bya link 89 which extends (FIGS. 3 and 7) leftwardly andthreadedly'engages in an adjusting device 90. The device 90 is slideablymounted but not capable of turning in a bracket 90A, and it isthreadedly engaged by an anchor shaft 9 so that by turning the shaft 91the link 89 can be actuated to swing the lever 88 for adjusting theslack in the chain 64.

The carriage 34 for the belt 35 is movable on rollers 49 in tracks 48 soit can be projected outwardly of the opposite ends of the frame 33 thatis fixed to the platform 27 of the dumbwaiter. The longitudinal movementof the carriage 34 is obtained by motor 93 (FIG. 3) disposed adjacent anupwardly opening U-shaped sub-frame 94 having side walls 95 and 96. Themotor pulley 97 is connected to pulley 98 by a suitable belt 99 anddrives shaft 100 operably mounted in the walls 95 and 96. The shaft 100extends through wall 95 and carries a sprocket 101 thereon in thecentral space between walls 73 and 95 (F1G. 9). A pair of idler shafts102 are supported above and to each side of the main shaft 100 (F168. 4and 9) in walls 94 and 95, and each shaft carries an idler sprocket 103.A carriage drive chain 104 is trained under the sprocket 101 and oversprockets 162. One end (right end as seen in FIG. 4) 105 of the chain104 is anchored at a bracket 106 carried under the horizontal wall 54 ofthe carriage 34. The opposite end 107 of the chain 104 is anchored at alike bracket 108 fixed to the wall 54. Rotation of the sprocket 101 inreverse directions will exert its driving force on the chain 104 andmove the carriage 54 in directions determined by the motor direction.

It can now be appreciated that the motor 93 drives chain 104 in aselected direction to move the carriage 34 left or right toward eitherof the tables 25 (FIG. 1 and 2). The motor 67, on the other hand, drivesthe belt 35 in a selected direction to move tote boxes B rel ative tothe frame 33. Simultaneously, the motor drives shafts 62 and 66 (NOS. 4and 7) upon the outer end portions of which are mounted friction rollers39 and 38 respectively.

For example, when the belt 35 (FIGS. 1, 2 and 4) is driven to move boxesB leftwardly the shafts 62 and 66 must be driven in a clockwisedirection in order to rotate the belt shafts 56 and 58 through the gears60 and 61 in a counter-clockwise direction. This operation drivesfriction rollers 38 in the clockwise direction such that upon engagementof rollers 38 with the friction rollers 40 on the lefthand table 25, thebelt 41 (FIG. 2) is driven leftwardly to move the box B leftwardly ontotable 25. This is a box unloading operation. When moving box 13 fromtable 25 onto the carriage belt 35 for loading, the shafts 62 and 66 arerotated in a counterclockwise direction so that, through the directionreversing gears 60 and 61, the carriage belt 35 is moved rightwardly atthe same time the carriage 34 is moved leftwardly toward table 25 toengage friction rollers 38 and 40 for driving table belt 41 rightwardly.Thus, a box B is loaded onto the carriage belt 35. During this operationof belts 35 and 41 the carriage motor 93 is driven in the appropriatedirection to move the carriage 34 out toward the lefthand table 25 andthen it is reversed to move the carriage back into the frame 33 on thedumbwaiter floor 27. Of course, by selecting the direction of drive formotor 93 the carriage 34 may be moved left or right, and by selectingthe direction of drive for motor 67 the belt 35 can be driven eitherleft or right while the friction rollers 38 and 39 are rotated in anopposite hand to the belt movement because of the gears 60 and 61.

THE WORK SUPPORTING TABLES As heretofore referred to in describing FIGS.1 and 2, each dumbwaiter shaft door opening 23 and 24 is provided with awork (boxes) supporting table 25 supported at a desired elevation offthe floor by a leg structure 26. Each such table has a slave beltoperably mounted thereon such that the belts form continuations of thecarriage belt 35. While a slave belt 41 or 43 is shown on tables 25 inthe drawing, it should be understood that other means can be employed,such as live rollers, gravity rollers, or equivalent load supportingconveyor means. Legs 26A at the shaft ends of the tables 25 serve tosupport the belts 41 and 43 at the desired alignment of belt 35 withbelts 41 and 43.

Belt 41 (FIGS. 10 and 11) is trained over roller carried on shaft 111.The outer ends of shaft 111 carry the slave friction rollers 40 so thatthe rollers 40 can drive the belt 41 in the same direction of rotation.The opposite end of belt 41 is trained about roller 113 carried on ashaft that is adjustably mounted in the table frame by means 114.. Thespan of the belt 41 between rollers 110 and 113 is supported on asurface 115, and the longitudinal edges of the surface 115 are flankedby guide members 116. The table 25 comprises longitudinal box beams 117and suitable cross members 118. The belt supporting portion of eachtable 25 may be provided with an outboard portion 25A which does nothave a slave belt, whereby boxes 8 can be temporarily stored waitingpick-up to remove the same by the dumbwaiter or waiting distribution onthe floor.

What has been described for the lefthancl table 25 is equally applicableto the belt 43 on the righthand table 25 of FIGS. 1 and 2.

THE CARRIAGE CONTROL SYSTEM The carriage 34, driven by motor 93, ispermitted to project a suitable distance so that the friction rollers 38and 39 are held against the table slave rollers 40 or 42 respectively,and this contact is maintained during the transfer operation. Theoutward travel of the carriage 34 is limited by contact between rollers33 and 40 or rollers 39 and 42. The return and centering subject to thelocation of limit switches 126 and 121, switch 120 (FIGS. 3, 4 and 5)being located near the shafts 101 and 102 such that its actuating roller122 is in the line of travel of an actuator cam 123. The slide plate123A is adjusted by a threaded stern 125 accessible (FIG. 3) from theleft end of the carriage 34. A similar cam 126 (FIG. 9) is provided toactuate the roller 127 for switch 121. The cam 126 projects down from aslide plate 126 that is adjustably connected to the under side of wall54 by a pair of mounting means 129 received in slots in the plate. Athreaded stem 130 (E16. 3) engages the plate and is accessible from theright end of carriage 34.

When the carriage 34 moves leftwardly in returning toward a centeringposition the cam roller 122 of limit switch 1211 will eventually rideoff the right end of the cam 123 and stop motor 93. Similarly, when thecarriage 34 moves rightwardly, the cam roller 127 will eventually rideoff the left end of the earn 126 and stop motor 93.

THE CONTROL SYSTEM It can be seen in HO. 1 that the upper surface of thecarriage, particularly the carriage top wall 52 is formed with spacedapertures 131 that are on opposite sides of the belt travel and nearopposite ends of the carriage. The distance between the apertures 131 isslightly less than the length of the boxes 13 to be handled.

The aperture 131 (FTGS. 3, 7 and 9) near the right end of the carriage34 receives a depressable roller 132 on the end of a feeler arm 133 foractuating a limit switch 134. Similarly (FIGS. 3 and 4) the leftaperture 131 receives a depressable roller 135 on the end of a feelerarm 136 for actuating a limit switch 137. The rol lers 132 and 135project above the top surface of the wall 52 and above the belt 35 sothat both will be engaged by the bottom of a centered box. Thedepressing of a roller 132 or 135 will control the motor 67 to stop belt35, whereby a box B can be quickly brought into a centered position onthe carriage 34.

Turning now to FIGS. 13 and 14, and to other appropriate views in thedrawings, it is seen that tables are provided with switches X and .Y(FIGS. 1, 11, 12 and 13) and the carriage 34 carries switches 134 and137. These switches perform dual functions as will presently appear.Switch X is connected into a circuit (FIG. 14) which initiates a boxloading operation from the lefthand table 25 and also serves as astopping means in the holding circuit during a box unloading operationto the left. Switch Y forms an element of the initiating circuit duringa box loading operation from the righthand table 25 and also serves as astopping means in the holding circuit during a box unloading operationto the right.

Switches 134 and 137 are connected into the initiating circuit for anunloading operation either to the right or to the left. Also, switch 134is a stopping element in the holding circuit during a load operationfrom the left. Similarly switch 137 is a stopping element in the holdingcircuit during a load operation from the right.

Switches 120 and 121 in conjunction with the respective cams 123 and 126(HQ. 3) are operative to return and center carriage 34 in the frame 33.When the carriage moves to the left cam 126 actuates the switch 121through roller 127 so that when the carriage movement to the left iscompleted, the carriage will automatically move back to the right to acentered position where the cam 126 runs off roller 127 of switch 121.Similarly, when the carriage 34 moves to the right cam 123 will actuatethe switch 120 through roller 122 so that when the movement is completedthe carriage 34 will automatically move back to the left to a centeredposition where the cam 123 runs off roller 122 for switch 120. Thus,when the carriage is centered the cams 123 and 126 are out of contactwith the respective switch rollers 122 and 127.

The control circuits for carriage left and carriage right movement (FIG.14) are both electrically and mechanically interlocked as are thecontrol circuits for the belts left and belt right movement.

THE LOADING OPERATION With the dumbwaiter car 26 positioned at apreselected landing, with the left hand car gate 28-29 and hatch door30-31 open, with no box B on the carriage 34 to depress rollers 132 and135 of switches 134 and 137 respectively, and with a box B on thelefthand table 25 to depress switch X, an initiating circuit is set upto load the box B from the left. Once the circuit is energized the motor93 will drive the carriage 34 to the left and will also energize motor67 to drive the carriage belt 35 to the right. Simultaneously, the loadfrom the left circuit becomes self-holding through the left maintainingcircuit under control of switch 134. As the carriage 34 starts itsmovement to the left, cam 126 closes switch 121 which sets up thecarriage return and centering circuit. The carriage 34 moves out to theleft with its belt 35 driven to the right. This action rotates frictionrollers 38 in a counter-clockwise direction. As the friction rollers 38engage the slave friction rollers 40 on the left table 25, table belt 41will be driven to the right to move the box B onto the belt 35 whichthen completes the loading of the box B onto carriage 34. Thus, box Bwill move rightwardly until it depresses roller 132-for switch 134 whichdeactivates the left maintaining circuit which, in turn, deactivates theload from the left circuit. Thus, the left drive of motor 93 and theright drive of motor 67 are deactivated. As the carriage left circuit isdeactivated it allows the carriage return circuit, previously set upthrough switch 121, to energize the motor 93 to drive the carriage 34rightwardly. The carriage 34 then returns into the frame 33 until cam126 releases roller 127 for switch 121, at which event the carriage willbe substantially centered in the frame 33.

Similarly, with a box B on the righthand table 25 to depress switch Y,and with no box on the carriage 34 to depress rollers 132 and 135 forthe respective switches 134 and 137, an initiating circuit is set up toload the box B from the right table 25. This circuit energizes motor 93to drive the carriage 34 rightwardly and energizes motor 67 to drive thecarriage belt 35 leftwardly. At this time, the load from the rightmaintaining circuits are set up under control of switch 137. As thecarriage 35 begins to move to the right, cam 123 activates switch 121)by depressing the switch roller 122 to set up the return circuit throughswitch 120. Thus, the carriage 34 moves to the right and belt 35 movesto the left which rotates the friction rollers 39 in a clockwisedirection. As friction rollers 39 contact slave friction rollers 42 onthe right table 25, the table belt 43 is driven leftwardly to move thebox B onto the carriage belt 35. The loading of the box 13 onto belt 35will depress roller 135 of switch 137, and this action deactivates themaintaining right circuit which, in turn, deactivates the load from theright circuit to stop motors 93 and 67. Deactivation of the rightcircuit allows the carriage return circuit to become active and thecarriage 34 is driven by motor 93 to the left for return into the frame33 until cam 123 runs off the roller 122 for switch as the carriagereaches its centered or near centered position. Of course, for rightloading the right hand car gate 28 and 29 and hatch door 3% and 31 mustbe open.

THE UNLOADING OPERATION The unloading operation is as follows: with thedumbwaiter 26 at a preselected landing and the gate 28-29 and hatch door30-31 open, with switch rollers 132 and depressed by a box B on carriage34, and with no box B on the left table 25 to activate switch X, aninitiating circuit is set up to unload the box 13 to the left table 25.This activates the carriage motor 93 to drive the carriage to the leftand activates the motor 67 to drive the belt 35 to the left.

Simultaneously, the left maintaining circuits are set up subject toswitch X, and as the carriage 34 moves out to the left cam 126 activatesswitch 121 by depressing roller 127 to set up the carriage return andcentering circuit through switch 121. in this leftward movement of thecarriage and belt 35 thereon, the friction rollers 38 will rotateclockwise to contact and drive slave friction rollers 1-0 on the lefttable 25. The table belt 41 drives to the left to pull the box B ontothe left table 25 until switch X is contacted.

Actuation of switch X deactivates the left maintaining circuit which, inturn, deactivates the unload to the left circuit. The motors 93 and 67are stopped and motor 93 is reversed to drive the carriage 34 to theright to return it to the frame 33. Cam 126 eventaully runs off roller127 of switch 121 to deactivate the motor 93 when the carriage 34 is inor near its centered position.

similarly, when a box B is on carriage 34, it depresses rollers 132 and135 to activate switches 134 and 137 respectively. As no box is on therighthand table 25, and the righthand gate 28-29 and door 30-31 are inopen position, an initiating circuit is set up to unload the box B tothe right. This condition activates the carriage motor 93 to drive thecarriage to the right and activates motor 67 to drive the carriage belt35 to the right. Simultaneously, the right maintaining or holdingcircuits are set up through switch Y.

When the carriage 34 moves to the right its cam 123 depresses roller 122to activate switch 120 and set up the carriage return circuit. Duringthis movement the belt 35 moves to the right and drives friction rollers39 counter-clockwise so that upon contact with the slave frictionrollers d2 on the right table the belt 43 on that table is driven to theright. Thus, the box B is transferred onto the right table 25 until itactivates switch Y. This action deactivates the right maintainingcircuits which, in turn, deactivates the unload to the right circuit sothe motors 93 and 67 are stopped and motor 93 is reversed to drive thecarriage 34 back into frame 33. The return movement of the carriagecauses cam 123 to release the roller ll22 for switch 120 which stopsmotor 93 with the carriage in or near its centered position.

The foregoing disclosure has reference to a presently preferredembodiment of the invention, but it is understood that modifications areto be included. It is to be understood that the block wiring diagram ofFIGS. 14 sets forth, without reference characters, but with appropriatelegends, a suitable wiring circuit arrange ment. The circuitconnections, per se, are not specifically noted, but the same areembodied in an elongated casing 140 which is located (F168. 3, 4, 7, 9and 13) to extend longitudinally of and near the center of frame 33.

We claim:

l. in load transfer apparatus the combination which includes: anelongated frame, an elongated carriage initially centered in said frameand movably supported by said frame for movement longitudinally relativeto said frame, a first load supporting surface operably mounted on saidcarriage, first motor means supported by said frame and operablyconnected to drive said first load supporting surface relative to saidcarriage, first drive means on said carriage rotatably driven by saidmotor means, a second load supporting surface operably disposed in axialalignment with said elongated frame and spaced therefrom, slave drivemeans operably connected to said second load supporting surface to drivethe latter, and second motor means supported by said frame and operablyconnected to drive said carriage relative to said frame to bring saidfirst drive means into driving contact with said slave drive meanswhereby said first motor means effects simultaneous driving operation ofsaid first and second load support ing surfaces, said first and secondmotor means being reversible to effect transfer of loads selectivelybetween said first and second load supporting surfaces, a controlcircuit operably connected to said first and second motor means toeffect reversible operation thereof, load responsive switch meansconnected into said control circuit and disposed in the path of a loadreceiving area on said first and second load supporting surfaces todetermine the operation of said first and second motor means, and othercontrol means in said control circuit responsive to movement of saidcarriage out of said centered position in said frame to return saidcarriage toward said centered position.

2. In dumbwaiter service apparatus, the combination which includes: aframe on the d'umbwaiter providing trackways; a carriage supported onand movable along said trackways; first power means operably connectedto said carriage to move the same in opposite directions from a firstposition substantially centered in said frame to a second positionhaving an end thereof extended from one end of said frame; load movingmeans operably carried by and adapted to move a load relative to saidcarriage; second power means operably connected to said load movingmeans to effect movement ofa load therein; drive means operably disposedadjacent the end of said carriage, said drive means being included insaid second power means; dumbwaiter service means spaced from said endof said frame and having a load supporting and moving surface thereon;and slave means operably mounted on said service means to drive saidsurface, said slave means being disposed in position to be engaged bysaid drive means on said carriage upon carriage movement into saidsecond position; first control means on said frame and carriagecooperatively positioned and operable upon carriage movement to saidsecond position to return said carriage to said first position; andsecond control means on said service means operably connected to saidfirst control means to set up carriage return operation.

3. The dumbwaiter service apparatus of claim 2 wherein said first andsecond control means are responsive to the presence of a load.

4. In vertically movable load transporters such as dumbwaiters andelevators, the combination of a vertically movable dumbwaiter car, loadtransfer apparatus which comprises a stationary table adjacent a loadingand unloading position for said car, said table having a load receivingand discharge end spaced from the path of vertical movement of said car,first load moving means operable on said table to move the load oversaid end, first friction wheel means operably connected to said loadmoving means on said table to rotate and effect load movement relativeto said table, a frame carried on the vertically movable car and spaceda predetermined substantially fixed distance from said table end,carriage means operable on said frame to move in a direction toward andaway from said table end to bridge the space between said table andframe, means on said frame and carriage to guide the movement of saidcarriage along a path assuring alignment of said carriage and tables,second load moving means operable on said carriage to move the loadrelative thereto, second friction wheel means on said carriage operablyconnected to said second load moving means, said first and secondfriction wheel means respectively on said table and carriage beingpositioned to abut each other by friction contact, the direction ofrotation of one of said friction wheel means determining the concurrentdirection of operation of said first and second load moving meansrespectively on said table and carriage for transferring a loadtherebetween across the space between said table and spaced frame, firstreversible motor means operably connected to one of said first andsecond load moving means to effect a load transfer, and secondreversible motor means operably connected to said carriage to effectmovement thereof, said second motor means selectively maintaining andbreaking said abutment between said first and second friction wheelmeans and also serving in a power on stalled condition as the only meansto maintain positive contact pressure between said first and secondfriction wheel means sufficient to accomplish load transfer, saidpower-on condition being maintained until completion of said loadtransfer.

5. ln elevator loading and unloading apparatus, a vertically movableelevator car, a frame on said car having track ways therein, said carframe being positionable selectively at any of several elevations by theelevator car, a carriage operably mounted on said track ways and guidedthereby to move between a first position substantially centered in saidframe and a second position having an end portion extending outwardly incantilevered position, first load moving means operably carried by saidcarriage, first friction wheel means on said carriage adjacent said endportion and operably connected to said first load moving means, a loadsupporting table located at certain of the frame elevations, said tablehaving one end spaced a substantially fixed distance from said firstposition of said carriage, second load moving means operably carried bysaid table and substantially aligned with said first load moving means,said first load moving means being positionable by said frame of theelevator in substantially the same plane with said secondv load movingmeans, thereby forming a continuation of each other, second frictionwheel means on said table adjacent said one end and operably connectedto said second load moving means, said first friction wheel means beingengageable with said second friction wheel means in said second carriageposition, means in said frame supplying power to drive said first loadmoving means and first friction wheel means concurrently, said firstfriction wheel means driving said second friction wheel means wherebysaid first and second load moving means move in the same direction tomove the loads therebetween, and other power means operably connected tosaid carriage to move the same between said first and second positionsand said other power means serving in a power-on stalled condition asthe only means to maintain said friction wheel means in sufficientengagement to effect rotation to accomplish load transfervwhen in saidsecond position, said power-on condition being maintained untilcompletion of said load transfer. 7

6. In load transfer apparatus, the improvement which includes astationary load supporting table, first load moving means on said table,friction wheel means on said table operably connected to said loadmoving means to drive the means selectively to move a load onto and offof the table, a load transporter movable along a path perpendicular tothe direction of movement of said load moving means and spaced from saidtable, a load transfer carriage operable on said transporter to extendto a position across the space between said table and transporter,second load moving means on said carriage, drive wheel means on saidcarriage operable to drive said second load moving means simultaneouslywith load transfer operation of said carriage, said drive wheel means onsaid carriage being aligned by said carriage in said extended positionto engage said friction wheel means on said table and determine thedirection of said first load moving means to coincide with the directionof movement of said second load moving means on said load transfercarriage, motor means connected to said carriage to drive said carriageinto and withdraw said carriage from the extended position, and controlmeans for said motor means to cause said motor means to serve by meansof a power on stalled condition as the only means to hold said drive andfriction wheels engaged during load transfer, said power-on conditionbeing maintained until completion of said load transfer.

1. In load transfer apparatus, the combination which includes: anelongated frame, an elongated carriage initially centered in said frameand movably supported by said frame for movement longitudinally relativeto said frame, a first load supporting surface operably mounted on saidcarriage, first motor means supported by said frame and operablyconnected to drive said first load supporting surface relative to saidcarriage, first drive means on said carriage rotatably driven by saidmotor means, a second load supporting surface operably disposed in axialalignment with said elongated frame and spaced therefrom, slave drivemeans operably connected to said second load supporting surface to drivethe latter, and second motor means supported by said frame and operablyconnected to drive said carriage relative to said frame to bring saidfirst drive means into driving contact with said slave drive meanswhereby said first motor means effects simultaneous driving operation ofsaid first and second load supporting surfaces, said first and secondmotor means being reversible to effect transfer of loads selectivelybetween said first and second load supporting surfaces, a controlcircuit operably connected to said first and second motor means toeffect revErsible operation thereof, load responsive switch meansconnected into said control circuit and disposed in the path of a loadreceiving area on said first and second load supporting surfaces todetermine the operation of said first and second motor means, and othercontrol means in said control circuit responsive to movement of saidcarriage out of said centered position in said frame to return saidcarriage toward said centered position.
 2. In dumbwaiter serviceapparatus, the combination which includes: a frame on the dumbwaiterproviding trackways; a carriage supported on and movable along saidtrackways; first power means operably connected to said carriage to movethe same in opposite directions from a first position substantiallycentered in said frame to a second position having an end thereofextended from one end of said frame; load moving means operably carriedby and adapted to move a load relative to said carriage; second powermeans operably connected to said load moving means to effect movement ofa load therein; drive means operably disposed adjacent the end of saidcarriage, said drive means being included in said second power means;dumbwaiter service means spaced from said end of said frame and having aload supporting and moving surface thereon; and slave means operablymounted on said service means to drive said surface, said slave meansbeing disposed in position to be engaged by said drive means on saidcarriage upon carriage movement into said second position; first controlmeans on said frame and carriage cooperatively positioned and operableupon carriage movement to said second position to return said carriageto said first position; and second control means on said service meansoperably connected to said first control means to set up carriage returnoperation.
 3. The dumbwaiter service apparatus of claim 2 wherein saidfirst and second control means are responsive to the presence of a load.4. In vertically movable load transporters such as dumbwaiters andelevators, the combination of a vertically movable dumbwaiter car, loadtransfer apparatus which comprises a stationary table adjacent a loadingand unloading position for said car, said table having a load receivingand discharge end spaced from the path of vertical movement of said car,first load moving means operable on said table to move the load oversaid end, first friction wheel means operably connected to said loadmoving means on said table to rotate and effect load movement relativeto said table, a frame carried on the vertically movable car and spaceda predetermined substantially fixed distance from said table end,carriage means operable on said frame to move in a direction toward andaway from said table end to bridge the space between said table andframe, means on said frame and carriage to guide the movement of saidcarriage along a path assuring alignment of said carriage and tables,second load moving means operable on said carriage to move the loadrelative thereto, second friction wheel means on said carriage operablyconnected to said second load moving means, said first and secondfriction wheel means respectively on said table and carriage beingpositioned to abut each other by friction contact, the direction ofrotation of one of said friction wheel means determining the concurrentdirection of operation of said first and second load moving meansrespectively on said table and carriage for transferring a loadtherebetween across the space between said table and spaced frame, firstreversible motor means operably connected to one of said first andsecond load moving means to effect a load transfer, and secondreversible motor means operably connected to said carriage to effectmovement thereof, said second motor means selectively maintaining andbreaking said abutment between said first and second friction wheelmeans and also serving in a power on stalled condition as the only meansto maintain positive contact pressure between said first and secondfriction Wheel means sufficient to accomplish load transfer, saidpower-on condition being maintained until completion of said loadtransfer.
 5. In elevator loading and unloading apparatus, a verticallymovable elevator car, a frame on said car having track ways therein,said car frame being positionable selectively at any of severalelevations by the elevator car, a carriage operably mounted on saidtrack ways and guided thereby to move between a first positionsubstantially centered in said frame and a second position having an endportion extending outwardly in cantilevered position, first load movingmeans operably carried by said carriage, first friction wheel means onsaid carriage adjacent said end portion and operably connected to saidfirst load moving means, a load supporting table located at certain ofthe frame elevations, said table having one end spaced a substantiallyfixed distance from said first position of said carriage, second loadmoving means operably carried by said table and substantially alignedwith said first load moving means, said first load moving means beingpositionable by said frame of the elevator in substantially the sameplane with said second load moving means, thereby forming a continuationof each other, second friction wheel means on said table adjacent saidone end and operably connected to said second load moving means, saidfirst friction wheel means being engageable with said second frictionwheel means in said second carriage position, means in said framesupplying power to drive said first load moving means and first frictionwheel means concurrently, said first friction wheel means driving saidsecond friction wheel means whereby said first and second load movingmeans move in the same direction to move the loads therebetween, andother power means operably connected to said carriage to move the samebetween said first and second positions and said other power meansserving in a power-on stalled condition as the only means to maintainsaid friction wheel means in sufficient engagement to effect rotation toaccomplish load transfer when in said second position, said power-oncondition being maintained until completion of said load transfer.
 6. Inload transfer apparatus, the improvement which includes a stationaryload supporting table, first load moving means on said table, frictionwheel means on said table operably connected to said load moving meansto drive the means selectively to move a load onto and off of the table,a load transporter movable along a path perpendicular to the directionof movement of said load moving means and spaced from said table, a loadtransfer carriage operable on said transporter to extend to a positionacross the space between said table and transporter, second load movingmeans on said carriage, drive wheel means on said carriage operable todrive said second load moving means simultaneously with load transferoperation of said carriage, said drive wheel means on said carriagebeing aligned by said carriage in said extended position to engage saidfriction wheel means on said table and determine the direction of saidfirst load moving means to coincide with the direction of movement ofsaid second load moving means on said load transfer carriage, motormeans connected to said carriage to drive said carriage into andwithdraw said carriage from the extended position, and control means forsaid motor means to cause said motor means to serve by means of a poweron stalled condition as the only means to hold said drive and frictionwheels engaged during load transfer, said power-on condition beingmaintained until completion of said load transfer.